Myocardial infarction I

Question 1

MI results from

Answer 1

rupture or erosion of a vulnerable plaque in the milieu of inflammation and procoagulation

Question 2

MIs result from a rupture or erosion of a vulnerable plaque in what milieu?

Answer 2

inflammation and procoagulation

Question 3

when a plaque ruptures, blood is exposed to inner plaque material resulting in activation of what substances?

Answer 3

platelets, thrombin generation, thrombus formation

Question 4

how does acute coronary syndrome (ACS) manifest?

Answer 4

unstable angina
non-ST elevation
STEMI

Question 5

what is the cause of an NSTEMI?

Answer 5

nonocclusive platelet rich white thrombus

Question 6

what is the cause of a STEMI?

Answer 6

occlusive fibrin rich red thrombus

Question 7

nonocclusive platelet rich white thrombi cause what type of MI?

Answer 7

NSTEMI

Question 8

occlusive fibrin rich red thrombi cause what type of MI?

Answer 8

STEMI

Question 9

are platelet rich white thrombi occlusive or nonocclusive?

Answer 9

nonocclusive

Question 10

are fibrin rich red thrombi occlusive or nonocclusive?

Answer 10

occlusive

Question 11

what are the features of vulnerable plaques?

Answer 11

nonobstructive 40-60% stenoses 
thin fibrous cap 
minimal lumen diameter less than 4mm 
large atherosclerotic burden 
would not produce an abnormal stress test

Question 12

what are the three primary classifications of an MI?

Answer 12

1. spontaneous MI caused by a primary coronary event
2. MI secondary to increased oxygen demand or decreased supply
3. sudden, unexpected cardiac death

Question 13

which groups present atypically for MI?

Answer 13

diabetics
women
elderly

Question 14

what is the MI presentation for diabetics, women, and elderly populations?

Answer 14

w/o chest pain
more SOB
more N/V
more fatigue

Question 15

do most ACS stem from soft or hard plaques?

Answer 15

soft

Question 16

STEMI requires immediate reperfusion with what therapies?

Answer 16

thrombolytic therapy

primary PCI

Question 17

what leads correspond to anterior MI? which artery is responsible?

Answer 17

V1-V4

LAD

Question 18

what leads correspond to inferior MI? which artery is responsible?

Answer 18

II, III, aVF

RCA, LCX (35%)

Question 19

what leads correspond to lateral MI? which artery is responsible?

Answer 19

I, aVL, and/or V5,6

diagonal branches of LAD, OM branches of LCX

Question 20

an inferior STEMI from a proximal occlusion can result in what associated condition?

Answer 20

right ventricular infarct

Question 21

what are the symptoms of right ventricular infarct?

Answer 21

constellation of hypotension with elevated neck veins and clear lung fields

Question 22

what lead should be checked in an inferior STEMI from a proximal occlusion resulting in a right ventricular infarct?

Answer 22

V4R

Question 23

what agents should be avoided in an inferior STEMI from a proximal occlusion resulting in a right ventricular infarct?

Answer 23

preload reducters (NTG) 
BB

Question 24

a CV exam for ACS may show what signs?

Answer 24

paradoxically split S2
S4
S3

Question 25

what is the most specific and sensitive lab marker for myocyte injury?

Answer 25

troponin

Question 26

what is the use of creatine kinase MB (CKMB) levels?

Answer 26

can help pinpoint age and onset of an MI since CKMB levels return to normal sooner (2-3 d)

Question 27

what is the first branch in the treatment decision tree for chest pain? what is the rationale?

Answer 27

ECG identifies who needs immediate reperfusion therapy

Question 28

what are two treatment agent options for atrial fibrillation with pre-excitation?

Answer 28

amiodarone procainamide